“One could be excused for assuming that wildfires in the western US worsen air quality across the rest of the nation only due to smoke transport, but that would be incorrect. Instead, Ma et al. showed that extreme wildfires in the west actually reduce fine particle concentrations in the eastern US by an amount comparable to the increases that they cause in the west (see the Perspective by Qian). They attributed this unexpected effect to weakened eastward transport of fire smoke and enhanced wet removal of air pollutants caused by heat-induced convection from fires. This mechanism actually reduces deaths and economic losses nationwide.”

From Science.